Fig. 4

Formation process and characterization of pH-sensitive shell–core BAF312@cRGD-CaP-NPs. a Schematic diagram of the BAF312@cRGD-CaP-NP formation process. b Nanosize indicated that the BAF312@cRGD-CaP-NP size was 109.9 ± 1.002 nm, with a PDI of 0.253 ± 0.006. TEM results indicated BAF312@cRGD-CaP-NPs were spherical and homogeneous. c, d The stability of BAF312@cRGD-CaP-NPs were tested for 7 days. e, g The average potentials of BAF312@cRGD-CaP-NPs in aqueous solutions of pH 7.4 and pH 6.0 were − 10.6 ± 0.056 mV and + 6.80 ± 0.013 mV, respectively. f, h HPLC assay showed the BAF312 release profiles from NPs or NPs modified with cRGD at pH 7.4 and 6.0